Electric-arc lamp.



PATENTED JAN. 10, 1905.

H. LUX.

ELECTRIC ARC LAMP.

APPLICATION FILED JUNE 9, 1904.

UNITED STATES Patented January 10, 1905 PATENT OFFICE.

TO THE FIRM OF ALLGEMEINE BELAUOHTUNGS UND HEIZ INDUS- TRIE AGTIEN GESELLSCHAFT, OF BERLIN, GERMANY.

ELECTRIC-ARC LAIVI P.

SPECIFICATION forming part of Letters Patent No. 779,948, dated January 10, 1905.

Application filed June 8. 1904. Serial No. 211,619.

To all whom, it Wtcty concern:

Be it known that I, HEINRICH Lox, a subject of the King of Prussia, Emperor of Germany, residing at Schoneberg, ncar Berlin,

' Germany, have invented certain new and useful Improvements in and Relating to Electric- Arc Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved arclamp, one form of which is diagrammatically illustrated in the annexed drawing.

5 The improved lamp comprises a solenoids, which may have differential coils, as shown in the drawing, or only a single coil. Within this solenoid a core a is movable, to which is fixed a tube a for guiding the upper carbon.

To the lower part of the said tube a is connected a ring g, provided with two projections 25, to which a holder f is loosely pivoted. When the lamp is workingthat is to say, when the solenoid-core a is upwardly attract- 5 ed the holder f is suspended and two sides of an aperture therein abut against the upper carbon 0. The latter is thus gripped and caused to take part in the movement of the solenoid-corea. When the current in the so- 3 lenoid 8 decreases owing to the consumption of carbon, the solenoid-core a descends and the lower and free end of the holder f abuts against an adjustable mechanism i'or instance, a screw it, carried by and taking into a plate 7 in theunder part of the lamp mechanism. The holder f is thus slightly rotated about its pivot and caused to release the carbon c, which descends by gravity. This of course causes the arc to be shortened, so that 4 the current in the solenoid increases and the core a is again attracted. The lower end of the holder f is thus removed from the abutment-screw it and is caused to grip the carbon 0 again, and the latter is lifted with the solenoid-core. In known arrangements of a similar kind the upper carbon receives current over the holder f. This arrangement is suitable for lamps in which thick carbons are used; but in small lamps with comparatively thin carbons burning is liable to occur at the places where 5 O the holder is in contact with the upper carbon,

so that the latter will not be fed downward in a regular manner. For this reason current is not in the improved lamp supplied to the upper carbon over the holder f; but special means are provided for supplying the currcnt through the tube a. The upper end of the carbon (2 is inserted into a resilient ferrule-like holder or clip (Z, provided with a projection 0, adapted to abut against the stop k, inserted into the upper end of the tube a. The lip (Z is also provided with a brush 5, consisting of a suitable number of thin wires, the ends of which are in contact with the interior of the tube a. The projection 0 extends above the brush 6, so that the wires of the latter will not be bent by contact with the stop 7;. The tube a is adapted to be conductively connected with one of the supply-mains, so that the upper carbon can be supplied with current in a reliable manner over the brush Z.

The lamp described is more particularly intended for working with low amperage, and the arc must be almost completely shut off from the outer atmosphere, since otherwise the life of the carbons would be very short. For this purpose the globe 0 is firmly pressed against the lamp-frame by means of three abutments, of which two, Z and Z, are shown in the drawing. The abutment Z is fixed to a spring m in such a manner that it can be moved away from the globe in order to allow of removing the latter. The abutments are preferably slightly upwardly inclined, so that the spring 472 also serves to press the globe firmly against the lamp-frame in order to pre vent the access of air to the arc.

Having described my invention, I claim- 1. The combination, with a lamp-frame, a solenoid carried by the upper part of the said frame and provided with a tubular core, and a plate secured to the lower part of the said frame and provided with an adjustable tappet; of a guide-tube secured in the said core and provided with a lateral projecting arm at its lower end, a carbon slidable in the said guidetube, and a holding-lever pivoted to the said arm and provided with a hole for engaging with the carbon and having its free end portion arranged to strike the said tappet when the carbon is lowered by the said core.

2, The combination, with a guide-tube included in an electric circuit and provided with a stop at its upper part, of a carbon slidable in the said tube, a clip engaging with the upper end portion of the said carbon and provided with a wire contact-brush for bearing against 

